A simple model for RPLC retention and selectivity of imidazole enantiomersusing beta-cyclodextrin as chiral selector

Using reversed phase liquid chromatography (RPLC), this paper investigates the enantioselectivity variations, in a series of weak polar R, S-imidazole derivatives, with beta-cyclodextrin concentration in the mobile phase over a wide range of column temperatures. These compounds are used for the trea tment of onychomycosis. The selectivity data obtained were assessed using a chiral recognition model, based on the formation of complexes between the solute molecule and the cyclodextrin cavity. Gibbs Helmholtz parameters (De lta(Delta H), Delta(Delta S)) between R- and S- enantiomers were determined from the logarithm of the separation factor, alpha, versus the reciprocal of the temperature plots. The thermodynamic results predicted that the enan tioselectivity mechanism was related to both the solute's bulkiness and the asymmetric carbon atom configuration.